From EP 784 418 A, it is known to produce three-dimensional molded conductor bodies by injection molding, starting from a printed circuit board which is furnished with electrical components, e.g. SMD (surface mounted device) components, and which is re-shaped at a bending site prior to being embedded by injection-molding with plastics to thereby place light-emitting diodes at this site towards the outer side of the molded conductive body. The printed circuit board is substantially stiff so that the bending-re-shaping as well as the embedding or injection-molding with plastics does not pose any problems. In the course of miniaturizing components, it is increasingly desired to use thin, flexible conductive track foils, i.e. foil-type circuit boards, instead of relatively thick printed circuit boards with conductive tracks applied thereon, the flexible conductive track foils moreover having the advantage that the most varying conductive track configurations can be realized by mass production in an extremely narrow space on such conductive track foils. An example of using such conductive track foils is disclosed in DE 197 32 223 A, where insulating material is applied between the conductive tracks and the conductive track foil as a whole is arranged in a function integration module.
It would be desirable to be able to inject plastics around such conductive track foils similar to other conductive structures so as to attain a hermetic seal, in particular for applications in automobile doors and the like. Yet because of the flexibility of the conductive track foils, this is not easily possible because when the hot plastics material is injected in the injection-molding die, the—unstable—conductive track foil would bulge under pressure in the free regions where it is to be kept at a distance from the mold surfaces, resulting in a displacement of the conductive track foil, and even in a tearing of the conductive track foils. Therefore, it has also been attempted to inject plastics material around conductive track foils such that the conductive track foil in a first step is caused to lie against a surface of the injection mold and the plastics material is injected onto the oppositely arranged side of the conductive track foil, and that after this plastic material has become hard, the obtained product comprised of the conductive track foil with the plastics molded onto one side thereof is brought into another injection mold where it is caused to lie against a mold surface with its plastics side, whereupon the still plastics-free second side of the conductive track foil is injection-molded with plastics. However, this procedure is cumbersome and complex since complete different injection-molding dies are required to carry out the injection-molding (wherein also a cooling step must be provided between the two injection steps so as to allow the plastics material injected thereon in the first step to become sufficiently hard), and it is also detrimental because the conductive track foils, particularly with components mounted thereto, are twice subjected to the stress by pressure and temperature when plastics material is injection-molded thereon.